1. Field of the Invention
The present invention relates to an input apparatus having a touch panel on which input operations are performed by a user, a control method for the input apparatus, and a computer-readable storage medium storing a program for causing a computer to implement the method.
2. Description of the Related Art
When a user performs an input operation on a touch panel with a finger, a pen, or the like, an input apparatus having the touch panel determines the input operation. Here, the input operation performed on the touch panel by the user with a finger, a pen, or the like is a combination of the following acts (gestures):
(1) an act of touching the touch panel with a finger, a pen, or the like (hereafter referred to as “touch-down”)
(2) an act of moving a finger or a pen in a state in which the finger or the pen touches the touch panel (hereafter referred to as “move”)
(3) an act of moving a finger or a pen off the touch panel (hereafter referred to as “touch-up”) Also, a state in which a finger or a pen touches the touch panel is referred to as touch-on, and a state in which a finger or a pen does not touch the touch panel is referred to as touch-off.
Examples of an input operation performed on the touch panel by combining the above-mentioned acts include a tapping operation, a dragging operation, and a flicking operation. The tapping operation is an operation to lightly tap a desired region on the touch panel with a finger, a pen, or the like, that is, an operation to perform touch-up immediately after touch-down without performing move. The dragging operation is an operation to perform move after touch-down as if to slowly move an object, and then perform touch-up. The flicking operation is an operation to move a finger or a pen touching the touch panel off the touch panel by quickly moving the finger or the pen a certain distance. In other words, the flicking operation is an operation to quickly drag a finger or a pen over the touch panel as if to flip the touch panel.
For such an input apparatus having the touch panel on which an input operation can be performed, there has been a demand to detect an input operation without error.
For example, as a method to detect an operation including move such as a dragging operation without error, there is a method that calculates an amount of change in the sensitivity of the touch panel, and determines whether move is directed toward left or right based on the calculated amount of change in sensitivity (see Japanese Patent Registration No. 04073448).
Also, there is a method that, when a user performs touch-down, sets a region of a predetermined size (a region of a minute size) around a position at which the touch-down has been performed, and when there is a move out of the set region, determines that the move is valid (see Japanese Laid-Open Patent Publication (Kokai) No. H06-161647).
However, according to the conventional detection methods, there may be a case where when a user performs a tapping operation, a minute movement of a finger or a pen unintended by the user during touch-on is detected, and it is erroneously determined that the tapping operation is an operation including move (for example, a dragging operation or a flicking operation), and as a result, an operation unintended by the user is input, and a process unintended by the user is performed.